Relation between welding heating and properties for low-carbon chromium ferrite steels

The effect of nitrogen on brittle failure of chromium ferrite steels containing less than 0.01%C, after heating to high temperatures has been studied. It is shown that low carbon chromium steels have different sensitivity to variations of embrittlement temperature. The steels containing 25%Cr, approximately 0.008% C and approximately 0.020%N2 are inclined to embrittlement after welding heating, i.e. their temperature of embrittlement grows up to -20 deg C from -30 to -60 deg C in the initial state). On the contrary, high temperature heating involved in welding impoves the resistance of low-nitrogen steels of 01Kh25 type (up to 0.003 - 0.004 % nitrogen) to brittle failure, i.e. the embrittlement temperature decreases from -60 to - 80 deg C